21738648635 has 16 divisors (see below), whose sum is σ = 28462341600. Its totient is φ = 15807440640.

The previous prime is 21738648601. The next prime is 21738648641. The reversal of 21738648635 is 53684683712.

It is a happy number.

It is not a de Polignac number, because 21738648635 - 2¹⁸ = 21738386491 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 368141 + ... + 423089.

It is an arithmetic number, because the mean of its divisors is an integer number (1778896350).

Almost surely, 2^21738648635 is an apocalyptic number.

21738648635 is a deficient number, since it is larger than the sum of its proper divisors (6723692965).

21738648635 is a wasteful number, since it uses less digits than its factorization.

21738648635 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62158.

The product of its digits is 5806080, while the sum is 53.

The spelling of 21738648635 in words is "twenty-one billion, seven hundred thirty-eight million, six hundred forty-eight thousand, six hundred thirty-five".